1. Field of the Invention
This invention relates in general to certain new and useful improvements in remote control access systems, and more particularly, to remote control access systems which are comprised of a receiver-control unit located at or near an enclosed environment, and one or more remote transmitters, and which systems are electronically programmable by any user without knowledge of the specific code used or operation of the system itself.
2. Brief Description of the Prior Art
Remote control systems are widely used in a large number of applications in which a receiver is located to control some type of electronic equipment and which is operable by one or more remotely located transmitters. Usually, these receiver-transmitter arrangements are radio frequency operated, although they can be operated with other forms of electromagnetic radiation or sound energy.
The remote control access systems may adopt the form of convenience systems such as garage door openers which control the opening and closing of a garage door, as well as security systems such as those providing controlled entry into vehicles and buildings. The area which is to be secured by the remote control access system is often referred to as "protected environment" or the "secured environment."
In recent years, and primarily due to the increase of theft, vandalism and burglaries, many home and vehicle owners have installed remote access control systems, such as security systems and remote controlled garage door systems. The vast majority of these security systems, when triggered, will generate an audible or visible alarm signal or otherwise a silent alarm signal transmitted to a security force, such as a police department to alert of an improper entry or an improper intrusion into the protected area. Many of these commercially available security systems are remotely operable, that is, they include a receiver capable of being operated from a remotely located transmitter for purposes of arming and dis-arming the security system.
The present state of the art in conventional automotive vehicle security systems usually includes an alarm section which may either generate an audible alarm, as for example, from a siren, a horn, or the like and may also often activate a visible alarm by operating any of the vehicle lights. Many of these commercially available vehicle security systems may also disable some portion of the vehicle engine system such as the ignition system, starter, fuel pump, or lock the engine compartment. Thus, in the event of an improper intrusion or attempted theft of the vehicle, the security system will cause initiation of an audible alarm or cause the lights to switch on and off and may also interfere with operation of the vehicle engine system.
The use of a transmitter and a receiver which have been pre-coded is generally standard with all commercially available remote control access systems and other remote control systems. In these transmitter-receiver combinations, the code, usually referred to as an encoded signal, is permanently encoded into the receiver.
In the remote control security systems, the transmitter is always pre-programmed with respect to the receiver and the code can't be altered or changed by the user. In other words, the receiver can only operate on the basis of a security code permanently encoded in that receiver and transmitted from a particular transmitter matched and sold with that receiver.
In addition to being quite limiting to and having a security exposure in case of a loss or stolen transmitter they also present many constraints on the manufacturers, customers and dealers of these security systems. For instance, if the user of one of these prior art security systems should lose his or her transmitter, it is necessary to obtain another transmitter which was not previously coded and have that transmitter properly matched and coded for the particular receiver.
The encoding of the transmitter entails, at very least, obtaining the particular code to introduce into the transmitter for activating the receiver. This encoding also includes the requirements of opening the transmitter and then mechanically coding the transmitter. Usually, the coding is accomplished by scratching conductive lines on a printed circuit board, closing or opening switches or the like. Some transmitters are provided with control boards having hole areas capable of being punched to provide a particular encoded signal. In any event, some form of mechanical action is usually required for encoding the transmitter after the latter has been opened.
Usually, most users of the remote control access systems are not capable of encoding the transmitters on their own, and therefore, must seek the assistance of the retailer or manufacturer of the system. The mere fact that the code for authorized actuation of the security system must be known by the selling dealer or manufacturer may inevitably lead to a breach of the security system itself, since the code is usually written to maintain a permanent record of the same. More importantly should the user wish to change the code because of a lost or stolen transmitter, both the transmitter and the receiver will have to be sent back to the manufacturer. This is a time consuming task which leaves the user without the security system, in addition to being costly.
In addition to the foregoing, if a user desires to have several transmitters operate the receivers of several remote control access systems, such as security systems or garage door systems, each receiver must be properly programmed with the proper code. As an example, if a person desired to operate, with the same remote control system, several vehicles and garage doors, it is necessary to have a receiver in each car and a receiver in each garage door system pre-programmed by a manufacturer. This necessarily requires custom design efforts which is very time consuming as well as costly.
Since most security systems and remote garage door openers operate with substantially less than one million code combinations it has been recently recognized that many commercially available electronic sequencing devices (often referred to as "electronic scanners") can, in effect, remotely decode that security code in a fairly short period of time. The electronic sequencers or scanners are capable of rapidly generating a large number of possible code combinations and when the right code combination has been generated, it will automatically disarm the security system. There is not any decoding-proof measure which is commercially available for preventing anyone from using an electronic sequencing apparatus to disarm a security system.